Jewellery and Watches

A Certina Bio Star Electronic stainless steel wristwatch, circa 1971-4, with ESA 9156 transistorised balance wheel movement, the signed silvered dial with applied baton numerals, featuring the biorhythm display, the three coloured dials for Intellect, Emotion and Fitness levels, with sweep seconds hand, in brushed steel case, with reference numbers 7500 1001 and 9073162 to the reverse, signed crown, and signed bracelet, with original red Certina box, watch head diameter 44mm. £200-300

The idea of biorhythms was introduced at the beginning of the 20th century by the Austrian psychologist Hermann Swoboda from Vienna and the German doctor Wilhelm Fliess from Berlln, claiming that everyone’s life is affected by rhythmic biological cycles and these can be calculated. The three cyclic rhythms are composed of: the physical, having a duration of 23 days, the emotional (28 days) and the mental (33 days).

Biorhythms became popular in the 1970s and this watch allowed you to assess your ‘good and bad days’ through the three colour discs for Intellect (red disc), Emotion (blue) and Fitness levels (green) for the current day. The fourth disc gave the day of the week. To enable the wearer to do this, when purchased, the watch was set up with the purchaser’s birth date.

The Bio Star watch uses the ESA 9156 transistorised balance wheel movement, and was the only watch produced to use this movement. The 9156 is essentially the same as the common 9154, but had the added complications for the biorhythms discs.